1873.] 471 [Chase. 



According to Wolf 267 



• " De La Rue, Stewart and Loewy 2G7 



" Herschel (Bianchi and Laugier) 268 



" Harmonic analogy, a* 267 



« « " a 269 



• COMPARISON OF PLANETARY SERIES. 



The closeness of the foregoing accordance may lend interest to a com- 

 parison of my own planeto-tactic series with those which have preceded 

 it. 



Jupiter, being about two' and a-half times as great as the aggregate 

 mass of all the other planets, may be regarded as forming with the Sun 

 a binary star. The mutual action of the two controlling orbs of the 

 system, is greatest at perihelion. A mean radius vector corresponding to 

 the Schwabe sun-spot cycle, would be (11.07)1 = 4.967, which corresponds 

 very closely with Jupiter's secular mean perihelion distance (4.9787, 

 according to Stockwell, which would give a cycle of 11.11 years). 



If the mean perihelion centre of gravity of the binary Star, Sun and 

 Jupiter, be regarded as the extremity of a linear pendulum, of which 

 the Sun's centre is the point of suspension, let us designate the distance 

 of the centre of oscillation of the pendulum from the point of supensiou 

 by a. 



it X a = major axis of solar orbit about c. g. of binary star = ft 



77 3 X ft = Mercury's mean perihelion distance =- y 



Tt X y = Earth's " " = <J 



7T X 8 = Asteroid at distance = 2 X Mars = e 



3i X e = Saturn's mean distance .= 'C 



it X C = Neptune's " = tj 



f t] = Uranus's mean aphelion distance = 



f t) = Saturn's " " = t 



T 2 2 rj = Jupiter's mean perihelion distance = x 



i x = Mars's mean aphelion distance = X 



\ x = Earth's mean distance = /v. 



\ y. = Venus' s " =v 



\ z = Mean of Mercury's and Venus' s mean distances = o 



J T x = Mercury's mean aphelion distance = - 



^l x = " " distance = p 



■fe x = " " perihelion distance = c 



It will be readily seen that all the terms of the foregoing centripetal 



*a, assuming Jupiter's radial centre of oscillation as the fundamental unit ; p. assuming 

 Earth's mean distance as the unit. 



